Radially inner annular element of a wheel hub provided with front toothing for transmitting torque

Abstract

An annular element of a wheel hub is provided with a front toothing for transmitting torque and including a plurality of teeth extending radially between a first diameter and a second diameter of the front toothing and having ridges. A first end of the teeth extend to a third diameter of the front toothing at which the teeth have a maximum height and a second end of the teeth extend to a fourth diameter of the front toothing at which the teeth have a minimum height. The ridges each have a section at which the teeth have a straight radial profile and is rounded. A ratio between the third and first diameters is greater than 0.9.

We claim: 
     
         1 . A radially inner annular element of a wheel hub, the annular element comprising:
 an annular body having an axis of symmetry and a first axial front end, a front toothing for transmitting torque formed on the first axial end and including a plurality of teeth arranged in a row about the axis of symmetry and extending radially between a first diameter of the front toothing bounded by first, radially outer ends of the plurality of teeth and a second diameter of the front toothing bounded by second, radially inner ends of the plurality of teeth, each one of the plurality of teeth being bounded axially by a ridge including:
 a radially outer, first radial section delimiting a first end of the tooth and presenting in radial section a first curvilinear profile, extending radially inwardly to a third diameter of the front toothing, at which the tooth has a maximum height measured in an axial direction; 
 a radially inner, second radial section delimiting a second end of the tooth and presenting in radial section a second curvilinear profile, extending radially outwardly to a fourth diameter of the front toothing, at which the tooth has a minimum height measured in an axial direction; and 
 an intermediate, third radial section bounded between the first and second radial sections and connecting the first and second ends of the tooth; 
   wherein the ridges of the plurality of teeth have a substantially straight radial profile along the third section;   wherein the first section of the ridge of each one of the plurality of teeth is configured so that a ratio of the third diameter of the front toothing to the first diameter of the front toothing is greater than 0.9.   
     
     
         2 . The annular element according to  claim 1 , wherein in a plane perpendicular and transverse to the axis of symmetry, the third section of each ridge of each one of the plurality of teeth is shaped as a circular arc connecting a pair of substantially flat opposite flanks of each tooth, arranged obliquely so as to converge radially with each other outward and toward the ridge. 
     
     
         3 . The annular element according to  claim 1 , wherein the ridge of each one of the plurality of teeth is arranged to form a predetermined first angle with a plane perpendicular and transverse to the axis of symmetry and passing through a midpoint of the profile of the second radial section of the ridge, the first angle having a value between four degrees and ten degrees. 
     
     
         4 . The annular element according to  claim 1 , wherein the front toothing includes a plurality of radial, channel-shaped depressions, each one of the plurality of teeth being flanked by two of the plurality of depressions so as to separate each one of the plurality of teeth from each adjacent one of the plurality of teeth, each one of the plurality of depressions being arranged so as to form a second predetermined angle with a plane perpendicular and transverse to the axis of symmetry and passing through a midpoint of the profile of the second radial section of the ridge of each one of the plurality of teeth, the second predetermined angle having a value of between four degrees and ten degrees. 
     
     
         5 . The annular element according to  claim 4 , wherein the value of the second predetermined angle is greater than the value of the first predetermined angle. 
     
     
         6 . The annular element according to  claim 1 , wherein the front toothing has a design diameter between the first diameter and the fourth diameter and a ratio of the second diameter to the design diameter is less than 0.65. 
     
     
         7 . The annular element according to  claim 6 , wherein a ratio of the fourth diameter to the design diameter is less than 0.7. 
     
     
         8 . The annular element according to  claim 6 , wherein a value of the design diameter depends on a range of an amount of torque to be transmitted by the toothing and is substantially equal to a difference between the first diameter and a length of the third section of the ridge of each one of the plurality of teeth measured parallel to the straight profile of the third section of the ridge of each one of the plurality of teeth. 
     
     
         9 . The annular element according to  claim 1 , wherein the annular element is part of an inner ring of a rolling bearing including a first annular raceway for rolling elements, an insert ring providing a second annular raceway for rolling elements being disposed on the inner ring, a first front end of the annular element including an annular collar upset against the insert ring so to lock the insert ring on the annular element and provided with the front toothing, the front toothing being formed by plastic deformation of the annular collar, a first end of the insert ring facing a same side as a first end of the annular element, the first end of the insert ring including a flat front face and an annular shallow recess is provided radially inwardly of the flat front face of the insert ring, the annular collar being partially housed radially within the annular shallow recess and projecting axially cantilevering outside of the annular shallow recess. 
     
     
         10 . A driven wheel hub connectable with a vehicle transmission to transmit torque from a constant velocity joint having a side face spline, the wheel hub comprising:
 a rolling bearing including an outer ring having a radially outer first flange, a plurality of rolling elements, and an inner ring carried by or comprising an annular element according to  claim 1  and an insert ring mounted on the annular element;   wherein the annular element is spindle-shaped and has a second flange at a second front end opposite the first front end, the second flange being configured to receive a vehicle wheel, the first front end including an annular collar providing the front toothing configured to couple with the side face spline of the constant velocity joint.